Computing scale



K. C. ALLEN COMPUTING SCALE Aug. 9, 1960 Filed Aug. 24. 195s TGI INVENTOR.

KENNETH C. ALLEN AT TORN EYS Patented Aug. 3, 1960 COMPUTING SCALEKenneth C. Allen, Dayton, Ohio, assignpr to The Hobart ManufacturingCompany, Troy, Ohio, a corporation of Ohio Filed Aug. 24, 1953, Ser. No.376,136

17 Claims. (Cl. 265--5) This invention relates to computing scales andmore particularly to a power operated scale for computing, indicating,and providing a printed record of a weighing transaction at a selectedunit price.

It is the principal object of the invention to provide a scale havingpower operated means for actuating indicators, printing mechanism, andthe like, which responds quickly and accurately to the Weighingoperation of the scale and which develops adequate power for operatingthe indicator, or printing a ticket, -as may be desired, to provide arecord of the transaction.

It is a further object to provide such a scale in which the effect ofvibrations to which the scale may be subjected is reduced or eliminated,the scale responding only to the application of a weight, and not tomere vibrations of the mechanism or the support on which it rests.

It is aslo an object to provide controls for operating the power drivemechanism swiftly, without hunting, and providing for the accurate andrapid stopping of the drive when the balance point is reached.

It is a further object to provide for transferring the source ofelectrical energizing from a high speed to a low speed connection,including preferably an intermediate drive speed also, and fordynamically braking the drive motor when decelerating to a stopcondition.

It is a still further object to provide such a scale which avoidsbacklash difliculties and in which the scale comes to rest always whilemoving in the same direction of travel, such as while travelingdownward.

It is an additional object to provide a scale in which the removal ofthe article from the scale following its weighing leaves the scale andpower operating mechanism in its previous position for a limited periodsufiicient to place the next article on the scale, without returning-toits zero position, thereby avoiding the time required for such returnand the unnecessary driving of the mechanism from a previous-weightposition to zero, and back to another weight position.

It is another object to provide a scale in which the application of adifferent weight, either larger or smaller than the previous article,within the normal period of delay, will terminate that delay and causethe scale immediately to complete the weighing operation of the nextarticle.

Other objects and advantages will become apparent from the followingdescription, the accompanying drawings, and the appended claims.

In the drawings- Fig. 1 is a combined schematic and diagrammatic viewshowing the essential features of the scale mechanism in associationwith the power drive, the indicating and printing mechanism, and thecircuits which provide for the desired operations; and

Fig. 2 is an illustrative view indicating the terminology andnomenclature employed in connection with the several relays involved inthe system.

Referring to the drawings, which disclose a preferred embodiment of theinvention, the scale is shown diagrammatically in Fig. l as comprising aplatter 10 for receiving the article to be weighed. The platter issupported through vertical members 11 on a double lever systemcomprising the main lever 12, floating links 13 and secondary lever 14.Any other lever arrangement such as a single lever and check link may beemployed 1f desired, and likewise any suitable form of counterbalancemay be used, a spring 15 being shown as connected to the lever andforming therewith the essential elements of the weighing mechanism. I

A movable contact 20 cooperates with fixed contact 21 forming a switchthat is open when the scale is with out weight in the platter. As shownsuch contact 20 is associated with the fulcrum strut 22 of the secondarylever and is carried on a light spring arm 23 insulated from the scalebut could be placed at any location between the platter and itssupports. Application however of a weight in excess of a predeterminedsmall amount to the platter 10 will cause contacts 20 and 21 to closeand remain closed as long as the weight is on the platter. As showncontact 20 is grounded to the frame of the mechanism.

The lever 12 has an extension arm 25 which carries a series ofcontactseach mounted on spring arms, and arranged to travel upwardly ordownwardly in accordance with the deflections of the lever. These springcontacts are mounted adjacent cooperating contacts carried on a contactcarrying assembly 27 which functions as a follow-up device. The contactson arm 25 include an upper contact 30 cooperating with a closely spacedcontact 31 on assembly 27, and a lower contact 32 similarly cooperatingwith a closely spaced contact 33 on assembly 27. Upon slight upwardmovement of arm 25 relative to assembly 27 it will be evident thatcontacts 30 and 31 will close, and conversely. on slight downwardmovement contacts 32 and 33 are closed.

Arm 25 also carries lower contact 34 arranged to cooperate with contact35 on assembly 27, the spacing between contacts 34 and 35 being somewhatgreater than that between contacts 32 and 33 and thereby requiring agreater deflection of the lever before closing of the circuit takesplace.

Still further, arm 25 carries upper contact 36 cooperating with contact37, and lower contact 38 cooperating with contact 39 on assembly 27, thespacing between such respective pairs being still greater so that theywill not close until a further deflection of the lever takes place.

The power operating mechanism includes a drive motor 50 having anarmature 51 and a field 52. The motor has a shaft 53 which is directlyconnected to an indicator or counter shown diagrammatically at 54. Suchindicator may beof the type having multiple drums on which figuresappear corresponding to the amount of rotation of the shaft, to furnisha direct reading indication varying in relation to the weight of thearticle on the scale.

Shaft 53 operates through worm gearing 56 to drive a screw 57 whichturns on nut 58 to raise or lower. the contact assembly 27. Thus inresponse to the operation of motor 50, the contact assembly 27 is raisedor lowered, carrying with it the series of contacts 31, 33, 35, 37 and39 which function as a follow-up device, as will be more fully describedhereinafter.

A printer is indicated diagrammatically at 60 operated by print motor 61and connected through shaft 62 with the drive motor 50 so that theprinter will be properly set in accordance with weight, through theturning of motor shaft 62, the amount of rotation of which is directlyrelated to the weight of the article. i

For purposes of illustration and simplicity of nomenclature, a typicalrelay is illustrated in Fig. 2, similar to the several relays embodiedin the circuit diagram of Fig.

- or full line position to their closed or dotted line position inresponse to such energization. Spring means 68 normally returns theswitch arms to their upper or open positions. Further, the contacts aredesignated in the manner shown, that is, the topmost switch arm in theopen position completes a circuit between contacts 1 and 2, and in theclosed position completes a circuit between contacts 2 and '3. Thesecond switch arm extends from contact '5 and moves from open positionagainst contact 4to closed position against contact 6, similarconnections being established by each of the switch arms of the relay.

The main power supply is indicated at 70 which may suitably be anordinary 110 volts A.C. source such as is available in locations wherethe scale would generally be used. A transformer 72 is provided havingone second ary, 73 which produces a supply source 74 of 110 volts AC.separate from the main power source and such that one side thereof canbe grounded to the frame of the scale Without danger of shock with theother side furnishing power for operating controls. A source of highvoltage D.C. is likewise desired and for this purpose a seleniumrectifier 75 is connected through condenser 76 to ground, therebyfurnishing a source 77 of approximately 150 volts D.C. likewise forcontrol purposes. A lower voltage direct current supply is likewisedesired and to provide this the transformer also incorporates anothersecondary winding 80 developing about volts which supplies the full waverectifier 81, the oppo- Site terminals of which furnish a source 82 ofabout 24 volts direct current as used in the system.

Assuming now that the scale is unloaded and with power supplied throughthe various circuits, the following conditions exist. Since there is noload on the platter, contacts 20 and 21 are open, so that an energizingcircuit is completed for the coil of No Load relay N from source 77through series resistor 85 and through coil N to ground. The N relay isthus closed. The Hold relay H is open because its only source of poweris through contacts N4 and N5, which circuit is broken. Fast relay F isopen since its energizing circuit is broken at contacts 36, 37 and 38,39. Up relay U and Down relay D are closed because they are energizedfrom source 77, through series resistors 86 and 87 respectively, throughthe operating coils of the relays to ground. It will be noted that relayU has a resistor 88 connected in parallel with its coil but thisresistor is ineffective because its circuit is broken at switch contacts30, 31. Relay D similarly has a resistor 89 in parallel with itsoperating coil but it also is ineffective because its circuit is openedat switch contacts 32, 33. The Anti-backlash relay A is closed becauseit is energiz ed from source 74 through its operating coil and throughrelay contacts U6 and US to ground. The Medium relay M is open becauseits energizing circuit is through contacts A9 and A8 which are closed,and through switch contacts 34 and which are open.

Control relay C is closed because a circuit is complet'ed from source 77through resistor 92, the operating coil of .relay C, contact-s D6 andD5, through contacts A12 and All to ground.

Printing relay P is closed through a circuit which is completed from oneside of power source 70, switch con tacts N8 and N9, through the coil ofrelay P and back to the other side of source 70. Upon closing, relay Plocks itself in through a circuit from the same side of source 70,contacts P3 and P2, through normally closed contacts 95 of a cam switchoperated by cam 96 controlled by the print motor 61, thereby providing abypass for the contacts of relay N as long as the cam switch contacts 95remain closed.

With both relays U and D in closed position, both sides of the motorarmature 51 are connected together, and thus the motor does not run. Thefield circuit to the motor field 52 is likewise open because itsenergizing circuit is broken at contacts C1 and C2.

Elimination of vibrations Vibration of the scale or its mechanismresulting from either the handling of the scale itself or fromvibrations or movements of the structure on which it is supported areobjectionable in the case of power operated weighing mechanism since ittends to cause undesired response of the drive motor and associatedparts to vibrations as distinguished from responding to the applicationof weight to the scale. In accordance with the present invention theeifect of vibration is materially reduced and largely eliminated so thatthe mechanism distinguishes between mere vibration, and deflection ofthe weighing mechanism in response to the application of a; load. Itresponds to the latter but makes no response to the former. This will beclear by the following analysis.

Assume that vibration occurs causing the scale lever 12 temporarily andfor short intervals to close its respec tive contacts 30, 31 and/ or 32,33. Closing of contacts 31 for example grounds resistor 88 through acircuit which is completed through normally closed contacts 97' actuatedby a cam 98 on the print motor shaft, such contacts being closed exceptwhen the printing motor is in operation. The grounding of resistor 88places it in shunt circuit to the operating coil of relay U. A similarcircuit may be traced when contacts 32 and 33 close, grounding resistor89 in shunt across the operating coil of relay D. The completion ofeither or both of these shunt circuits reduces the effective voltage onthe operating coils of the relays U or D from a normal of about volts toabout 4 or 5 volts. This low voltage is not sufficient to maintain therelays in closed condition but because of the inductive effect of thewindings of the coils, and the effective short circuiting of the coil byresistor 89, current continues to flow for a fraction of a second andthere is a short delay before the flux collapses sufiiciently to allowthe relays to open. This delay may be varied if desired, a typicalexample being to provide for a delay of a tenth to a twentieth of asecond. Consequently, even severe vibrations of the scale mechanism,suflicient to cause repeated momentary closing of contacts 3033, willhave no effect on the operation of the scale and the motor will remainat rest.

Weighing operation Assuming now that a weight or load is applied toplatter 10, and that the amount of the weight is small, deflection oflever 12 occurs with corresponding downward travel of arm 25 to anextent suflicient only to cause the closing of contacts 32 and 33, butinsufiicient deflection to cause the closing of either contacts 34, 35or contacts 38, 39. Closing of contacts 32, 33 completes a circuit fromground, through closed contacts 97, contacts 32, 33 and contacts A3, A2to resistor 89 which thus reduces the potential applied to the coil ofrelay D. After the above indicated short delay period, relay D opens,and in doing so its contacts D5 and D6 open the ground circuit for thecoil of relay C allowing this relay to open at approximately the sameinstant. With relays D and C in open position, the low voltage D.C.source 82 supplies the motor field through a circuit from the plus sidethereof through contacts C1, C2, contacts M7, M8, through the fieldwinding 52, contacts M2, M1 to the negative side of the source. Themotor field is thus energized. Likewise the armature is energized fromthe same source, through a circuit from the plus side, contacts C1, C2,contacts M10, M11, contacts U3, U2 to v the armature, contacts D2 andD1, and contacts M5, M

to the negative side of the line. The motor is thus energized and runsat slow speed in the direction to turn shaft 53 and to operate screw 57in the direction to move contact assembly 27 in the downward direction.As this movement continues, it is recorded-in counter 54 and likewiseprovides for actuation of printer 60. 7

Such conditions continue until the lever stabilizes at a balanceposition and until the downward travel of the contact assembly 27results in the opening of svw'tch contacts 32, 33. Promptly upon theopening of these latter contacts the shunt circuit through resistor 89is broken and the full voltage of source 77 is appliedthroughresistor 87to the coil of relay D, causing this relay to close immediately. In sodoing, the circuit through the armature 51 is broken bythe opening ofcontacts D1 and D2 and with the closing of contacts D2 and D3, thearmature is short circuited upon itself through contacts U2 and U3. Thusthe scale automatically senses arrival at the balance condition,whatever interval may be required for that operation, and at this timerelays U and D are both operated, thereby setting up the conditions forthe operation of relay C which in turn controls the printing operation.

The closing of contacts D and D6 connects the operating coil of relay Cto ground through a circuit including contacts A12 and All but acondenser 100 is connected in shunt to the coil and hence the coil doesnot receive operating voltage immediately, and there is a short timedelay during which the charge builds up on condenser 100 throughresistor 92. Such condenser 100 has previously been maintained in adischarged condition by a grounded circuit through contacts U4 and US orD4 and D5 in combination with A12 and All, or both. After such delay,which may be of the order of one-half second, the potential has risensufiiciently and relay C closes. Until it does close, however, theenergizing circuit for the motor field coil 52 remains as previouslydescribed through contacts C1 and C2 and hence a high degree of dynamicbraking is produced, causing the motor to come quickly to a stop. Thisdelay not only provides for the dynamic braking but also provides ashort period to assure that complete stability of the weighing and powerdrive mechanisms has been attained. The time delay in the operation ofrelay C requires that the scale remain in balance for this briefinterval before the printing operation begins and if for any reasonthere is a disturbance the time interval is reestablished. Uponoperation, relay C conditions the circuit for the prompt initiation ofthe printing operation without further delay or any'manual operation. Itwill be seen from the above that it is impossible for the scale to printunless it is in balance and that if anything disturbs that balance or ifan attempt should be made to tamper with the weight,

relay C will not operate and the printing operation cannot take place.

- Printing operation In response to the closing of control relay C, itscontacts C5 and C6 supply power through a circuit from one side ofsource 70, contacts N8 and N7 of relay N which is open, contacts C5 andC6, contacts P5 and P6 to the printer motor 61 and back to the otherside of source 70. This actuates the motor to perform a printing cyclecausing the printing of a ticket showing the weight corresponding to thecondition established by the turning'of shaft 62. Immediately upon thestart of the printing operation contacts 97 are opened by the action 6.place. As the balance point is approached, contacts the C relay duringthe printing operation which thus continues through one cycle until cam96 opens contacts 95. When this occurs the locking circuit for the coilof relay P is broken and relay P opens and remains open even during thecoasting of the printing motor which does carry far enough to result inthe closing of switch contacts 95. The printer is now restored to itshome position and contacts 97 have closed and the scale is ready to beoperated or to start operating automatically if the balance condition isdisturbed. The printer, however, cannot recycle until the load has beenremoved from the platter thus opening contacts 20 and 21 and causing the-N relay to close, resetting and locking the P relay. Furthermore theprinter Will not operate at zero load even though the scale is inbalance because of the closed position of the N relay which breaks theprinter source of power through contacts N7 and N8.

Thus the system prevents operation of .the printer at zero load,prevents operation of the printer while the scale is in an unbalancedposition, prevents operating of the scale while the printer is inaction, and prevents recycling of the printer until the weight has beenremoved from the platter.

Weighing of larger loads Assuming now that a somewhat larger load hasbeen placed on the platter resulting in the deflection of lever 12 andarm 25 sufficiently to cause the closing of both contacts 32, 33 and 34,35. Closing of contacts 32, 33 provides for the closing of relay D afterthe previously described short delay interval. Closing of contacts 34,35 completes an energizing circuit for the coil of relay M which may betraced from source 74 through the operating coil of relay M, contactsA8, A9 and contacts 35, 34 to ground through closed contacts 97. Relay Mthereupon closes resulting in changing the connections to motor 50 froma direct current shunt connection to a modified series motor directlyconnected to the AC. source 70. This circuit may be traced from one sideof source 70, resistor 105, contacts M12, M11, contacts D3 and D2, thearmature 51 of the motor, contacts U2, U1, contacts M5, M6, M9, M8, thefield winding 52 of the motor, contacts M2, M3, contacts H2 and H1, orN2 and N1, to the other side of the line. Since relay F is open,resistor 106 is also connected through contacts F1 and F2 in such amanner that it is in shunt across the armature 51, resistor being inseries with the combination and with the motor field and armature beingin series with each other. This connection results in a slower speedoperation of the motor than would be the case if resistors 105 and 106were not present, but a substantially faster operation than when themotor was connected for slow speed. The series resistor 105 reduces thespeed of the series connected motor in the normal manner and theresistor 106 connected in shunt to the armature increases the torque atsuch lower speed by reason of creating a stronger field. Under theseconditions the system operates at medium speed with the motor connectedas a series motor and traveling substantially faster than its slow speedcondition.

' Application of maximum load Dynamic braking As the contact assembly 27travels downward at maximum speed, the following sequence of operationstakes 38 and 39 open, resulting in the opening of relay F. This resultsin the reinsertion of series resistor 105 and in the shuntconnectionofresistor 106 across the motor armature. lnsuch connection resistor 1,06serves as an effective dynamic brake and quickly slows the travel of themotor from high speed to medium speed. Further travel of the motorcontinues at medium speed until contacts 34 and 35 open, which resultsin the opening of relay M, disconnecting the motor from its A.C. supplysource 70, and reconnecting it for operation as a DC. shunt motor tosource 82. Because of the shunting efiect of the field on the armaturedynamic braking again takes place, quickly slowing the motor from mediumto slow speed. Further travel continues at slow speed, with the finalstopping vof the motor with dynamic braking in response to the openingof contacts 32, 33 at the balance point, in the manner described above.Also as described .the printing operation then takes place.

Anti-backlash feature Since the power drive motor 50 operates throughgearing to control the indicator, the travel of the contact assembly 27and the printer, it is desirable to provide for stopping of the systemat the balance point only while traveling in one predetermineddirection. Normally the scale will be deflected downward by theapplication of a weight, and the motor 50 will operate to cause thecontact assembly 27 to travel downwardly with correspond ing actuationof indicator 54. As the balance point is approached, the speed of thisoperation is progressively reduced and under normal conditions thebalance point is reached without over-travel. Hence the various parts ofthe mechanism including the gearing are not subject to errors due tobacklash. If however the scale should over-travel, the controls wouldprovide for the reverse operation, and if the balance point were reachedwhile traveling in the reverse direction, the mechanism would be subjectto backlash errors. Accordingly means are provided in accordance withthe invention for bringing the scale to a final balance only whentraveling in the same direction, that is, the normal direction ofincreasing weight or in the downward direction.

Assuming the scale has over-traveled, the closing of contacts 30, 31results in the opening of relay U and the opening of contacts U and U6.This breaks the circuit for the energizing of relay A, causing thatrelay to open. Upon opening, relay A establishes a bridging circuitacross contacts 30, 31 through its contacts A10, A11, therebymaintaining the deenergizing circuit for the coil of relay U, regardlessof the condition of contacts 30,31. The opening of contacts A2, A3disconnectsthe energizing circuit for the D relay from control ofcontacts 32, 33 so that the D relay cannot be opened even thoughcontacts 32, 33 should close. The opening of contacts A8, A9 and theclosing of contacts A8 and A7 disconnects the circuit for the energizingof the coil of relay M from its normal control contacts 34, 35 and locksrelay M in its closed position. The A.C. power source 70 is thusconnected to the motor in the same manner as described above with themotor field and armature being connected in series, but with relay Uopen and relay D closed, the connections to the motor armature arereversed and thus the motor is connected for medium speed operation inthe up direction, being energized through the resistor 105 in thecircuit of supply source 70 and with resistor 196 connected in shuntwith its armature.

At the same time the opening of relay A has connected contacts 34, 35through contacts A5, A4 to its own operating coil in such a manner thatwhen contacts 34, 35 are again closed relay A will close. The scale nowproceeds upward at medium speed through the balance point and beyondthat point until it has overtraveled sufficiently in the upwarddirection to cause the closing of contacts 34. 35. It may be pointed outthat if the unbalance is sutficient to result in the closing of contacts36, 37, this upward travel will take place at fast or high speed,progressing to medium speed when contacts 36 and 37 open, until suchtime as contacts 34 and 35 are closed.

When this point is reached, relay A closes, thereby unlocking relays Uand D and restoring contacts 34, 35 to their normal function ofcontrolling relay M. With relays U and D unlocked, contacts 32 and 33assume control andthe scale then proceeds onits normal downward strokeuntil these contacts open at the balance point, thereby assuring thatthe scale will come to balance only whiletraveling in the downwarddirection.

Removalof load from the scale Upon removal-of the load from the scale asequence takes place similar to that described above in connection withthe anti-backlash feature, and motor 50 travels in the reverse o'rupward direction at either medium or fast speed. In addition to thiscontacts 20 and 21 will open if the entire load is removed.

Holding function In the repeated weighing of articles of somewhatsimilar weights, removal of each article at the end of its weighingoperation would normally cause the scale to start its upward movementand that movement would continue until the scale had reached balance atthe Zero position. Thereafter when the next article was placed on theplatter the scale would start from zero and go through the completeweighing operation to reach balance at the new weight, perhaps almostthe same as the first weight. This would result in excessive andunnecessary functionings of the mechanism as well as loss of time whilethe scale went through the operations necessary to rebalance at the newload. In accordance with the present invention the necessity forreturning to zero between successive weighings is eliminated, and meansare provided which will retain the scale without returning to zero for alimited period of time following the removal of one article, andaffording-a sufficient opportunity to place another article on theweighing platter. The scale then starts from the position of deflectionwhich it occupied on the basis of the first weighing operation, andWithout delay either increases or decreases as necessary to arrive atthe-proper balance point for the weighing of the second article. Ifafter removal of the first weight no new article is placed on the scalefor the predetermined interval, the scale then returns to zero andbalances at that position.

This is accomplished through the provision of contacts 20, 21 and relaysH and N. Contacts 20, 21am mounted on the fulcrum end of lever 12 on aresilient member such that they will open when there is no load on theplatter and will close in response to the placing of a relatively lightload thereon.

The scale will operate in the manner already described whether or notcontacts 20, 21 are closed. If however the'weight on the platter issulficient to cause these contacts to close, they provide for closing ashunt circuit around the operating coil of relay N through resistor Eli)so that after a short delay interval (similar to that 2, therebyestablishing a parallel path so that the system continues. to besupplied and to operate in the normal manner. "Hence the scale will.respond immediately if the weight on the platter-is changed.

Assuming now that the weight is removed from'the platter, contacts 20,21 open and immediately relay N closes thus opening its contacts N1 andN2 and disconnecting the AC. supply 70. If vibration of the resilientlymounted contacts 20, 21 should occur in conjunction with the oscillationor vibration of the platter and lever system of the scale, the eifect ofthat vibration will be excluded and relay N will respond only to a clearand maintained closing of the contacts as distinguished from thevibratory closing thereof in the manner and for the reasons describedabove in connection with relays U and D.

Upon the opening of relay contacts N4 and N5 the supply source for thecoil of relay H is interrupted but the relay is maintained closed for adefinite interval through the connection of a condenser 115 in circuitwith resistor 111 and the operating coil, the condenser having beenfully charged during the time that relay N was open. Thus relay H doesnot immediately open and may be caused to remain closed for an intervalsufficient to afford an opportunity to remove one article from the scaleand to place another thereon, a typical such interval being a period ofabout five seconds. During this time there is no alternating currentsupply available for the scale motor since the motor depends solely uponalternating current for travel in the upward direction as describedabove in the anti backlash feature, and hence the scale cannot run. Thescale thus remains where it was when the load was removed. If anotherload is placed on the platter the five second delay period, contacts 20,21 again close, relay N opens, and the scale starts in operation readyfor a repetition of the cycle. If no weights are applied to the scale,then at the end of the five second period relay H opens, A.C. power issupplied through contacts H1 and H2, and the scale automatically returnsto its zero balance position in the manner described above.

The invention thus provides a novel and highly satisfactory scalemechanism which afiords ready and accurate response in relation to theweight, which develops adequate power for the operation of printers andthe like, and which is free of objectionable vibration ef fects.Likewise the scale avoids unnecessary work in a series of weighedoperations, and always comes to the balance point from the samedirection of travel thereby eliminating objectionable effects ofbacklash.

While the form of apparatus herein described constitutes a preferredembodiment of the invention, it is to be understood that the inventionis not limited to this precise form of apparatus, and that changes maybe made therein without departing from the scope of the invention whichis defined in the appended claims.

What is claimed is:

l. A power operating weighing scale having weighing mechanism and alever adapted to occupy a no-load position and to be deflected away fromsaid position in response to the application of a load to the scale,comprising a plurality of contacts movable with said lever, a follow-upmember carrying contacts cooperating respectively with said levercontacts, respective pairs of said contacts being arranged iwithdifferent spacings from each other providing for-closing of a moreclosely spaced pair upon a small deflection of said lever and theclosing of a more widely spaced pair upon a greater deflection of saidlever, certain of said contacts being located for closing respectivelyin response to opposite directions of travel of said lever, a drivemotor having a shaft the rotation of which corresponds to the weight,means connecting said shaft to move said follow-up member in response tothe rotation of said shaft, means controlled by said respective pairs ofcontacts for causing said motor to run continuously at high speed in onedirection in response to the closing of said widely spaced contacts,means for causing said motor to run continuously at slow speed in thesame direction in response to the closing of said closely spacedcontacts, means for causing said motor to run at high speed in theopposite direction in response to the closing of said certain contacts,means for stopping said motor in response to the opening of said closelyspaced contacts, and means for preventing stopping of said motor whensaid motor is traveling in said opposite direction and thereby causingoperation of said motor in said opposite direction until said shaft hasovertraveled sufliciently to effect reversal of the direction ofoperation of said motor and ultimate stopping of said motor Whiletraveling in said one direction.

2. A power operated weighing scale having weighing mechanism and a leveradapted to occupy a no-load position and to be deflected away from saidposition in response to the application of a load to the scale,comprising switch contacts mounted on opposite sides of said lever andmovable therewith, a followup member having oppositely located contactsarranged for cooperation with said pair of lever contacts to beselectively closed in accordance with the direction of movement of saidlever, a drive motor having a shaft the rotation of which isproportional to the weight of the load, weight indieating mechanismoperable in relation to the rotation of said shaft, means connectingsaid shaft to cause movement of said follow-up member selectively inaccordance with the deflections of said lever to effect the opening ofboth pairs of said contacts at a balance point when said follow-upmember has traveled a distance corresponding to the deflection of saidlever, means defining a circuit including one of said pairs of contactsfor reversing said motor toreturn said shaft and follow-up member totheir no load position, means responsive to removal of the load fromsaid scale for actuating said circuit means, and means including a partof said circuit means for effecting a time delay in the completion ofsaid circuit following removal of said load and operation of saidresponsive means and thereby effecting a correspending time delay in thereturn of said shaft and followup member to their no-load position.

3. A power operated weighing scale having weighing mechanism and a leveradapted to occupy a no-load position and to be deflected away from saidposition in response to the application of a load to the scale,comprising switch contacts mounted on opposite sides of said lever andmovable therewith, a follow-up member having oppositely located contactsarranged for cooperation with said pair of lever contacts to beselectively closed in accordance with the direction of movement of saidlever, a drive motor having a shaft the rotation of which isproportional to the weight of the load, weight indicating mechanismoperable in relation to the rotation of said shaft, means connectingsaid shaft to cause movement of said follow-up member selectively inaccordance with the deflections of said lever to effect the opening ofboth pairs of said contacts at a balance point when said follow-upmember has traveled a distance corre sponding to the deflection of saidlever, means defining a circuit including one of said pairs of contactsfor reversing said motor to return said shaft and follow-up member totheir no-load position, means responsive to removal of the load fromsaid scale for actuating said circuit means, means including a part ofsaid circuit means for effecting a time delay in the completion of saidcircuit following removal of said load and operation of said responsivemeans and thereby effecting a corresponding time delay in the return ofsaid shaft and follow-upmember to their no-load position, and meansresponsive during said delay to the application of a new load to saidscale for terminating said delay and thereby causing immediate operationof said motor toward a new balance point corresponding to said new load.

4. A power operated weighing scale having weighing mechanism and a leveradapted to occupy a no-load position and to be deflected away from saidposition in re:

sponse to the application of a load to the scale, comprising switchcontacts mounted on opposite sides of said lever and movable therewith,a follow-up member having oppositely located contacts arranged forcooperation with said pair of lever contacts to be selectively closed inaccordance with the direction of movement of said lever, a drive motorhaving a shaft the rotation of which is proportional to the weight ofthe load, means connecting said shaft to cause movement of saidfollow-up member selectively in opposite directions in accordance withthe deflections of said lever to effect the opening of both pairs ofsaid contacts at a balance point when said followup member has traveleda distance corresponding to the deflection of said lever, printing meanscontrolled by said shaft for printing a record of the weight of eachload, means operable automatically to activate saidprinting means inresponse to reaching of the balance position by said shaft, meansincluding one of said pairs of contacts for reversing the connections tosaid motor to return said shaft and follow-up member to their no-loadposition upon removal of the load from said scale, and means providing adelay in the return of said shaft to its no-load position followingremoval of said load and the closing of said one pair of contacts.

5, A power operated weighing scale having weighing mechanism and a leveradapted to occupy a no-load position and to be deflected away from saidposition in response to the application of a load to the scale,comprising switch contacts mounted on opposite sides of said lever andmovable therewith, a follow-up member having oppositely located contactsarranged for cooperation with said pair of lever contacts to beselectively closed in accordance with the direction of movement of saidlever, a drive motor having a shaft the rotation of which isproportional to the weight of the load, means connecting said shaft tocause movement of said follow-up member continuously and selectively indirection in accordance with the deflections of said lever to eifect theopening of both pairs of said contacts at a balance point when saidfollow-up member has traveled a distance corresponding to the deflectionof said lever, anti-backlash means responsive to closing of one of saidpairs of contacts for causing said motor to run in one directioncontinuously until said shaft has overtraveled sufficiently to effectclosing of the other of said pair of contacts for operation of saidmotor in the reverse direction in order to effect stopping of said motoronly when said other pair of contacts is opened by travel of said motorin said reverse direction, printing means controlled by the rotation ofsaid shaft for printing a record of the weight, and means operableautomatically after said scale has reached a balance condition toactivate said printing means.

6. A power operated scale having weighing mechanism and a lever adaptedto occupy a no-load position and to be deflected away from said positionin response to the application of a load to the scale, comprising adrive motor having a shaft, means including switches located foractuation by said lever forming a circuit controlling the energizationof said motor to cause rotation of said shaft in proportion to the load,means responsive to removal of the entire load from said scale forbreaking said circuit and thereby blocking operation of said tor toreturn said shaft to its no-load position, and means forrte-establishing said circuit upon application of a second load to saidscale.

7. A power operated scale having weighing mechanism and a lever adaptedto occupy a no-1oad position and to be deflected away from said positionin response to the application of a load to the scale, comprising adrive motor having a shaft adapted to actuate mechanism providing anindication of the weight, means including switches located for actuationby said lever forming a circuit controlling the energization of saidmotor to cause rotation of said shaft in proportion to the load, meansfor automatically breaking said circuit in response to removal of theentire load from said scale in order to deenergize said motor andthereby to leave said shaft in its position corresponding to the weightof said load, and means for re-establishing said circuit uponapplication of a second load to said scale to reenergize said motor andcause rotation of said shaft selectively in direction and amountcorresponding to the difference in said two loads.

8. A power operated scale having a weighing mechanism and a leveradapted to occupy a no-load position and to be deflected away from saidposition in response to application of a load to the scale comprising adrive motor having a shaft, means operatively associated with said leverto control the energization of said motor in forward or reversedirections selectively in accordance wit-.1 the deflections of saidlever, mechanism, operated by said shaft for producing an indicationcorresponding to the weight of said load, means responsive to theremoval of the load from the scale, and means controlled by said removalresponsive means for preventing a second operation of said indicatingmechanism until after the removal of the load from said scale.

9. A power operated scale adapted for the rapid weighing of a series ofloads and having a weighing mechanism and a lever adapted to occupy ano-load position and to be deflected away from said position in responseto the application of a load to the scale, comprising a reversible drivemotor having a shaft adapted to be displace from a no-load position to aposition corresponding to he weight on the scale, control means actuatedin response to deflections of said lever for selectively controlling theenergization of said motor to cause displacement of said shaft in anamount proportional to the load on the scale, switch means responsive toremoval of the load from the scale, and means controlled by said switchmeans following removal of the load for delaying the return of saidshaft to its no-load position pending the application of another load tothe scale.

10. A power operated scale adapted for the rapid weighing of a series ofloads and having a weighing mechanism and a lever adapted to occupy ano-load position and to be deflected away from said position in responseto the application of a load to the scale, comprising a reversible drivemotor having a shaft adapted to be displaced from a no-load position toa position corresponding to the weight on the scale, control meansactuated in response to deflections of said lever for selectivelycontrolling the energization of said motor to cause rapid displacementof said shaft in an amount proportional to the load on the scale, switchmeans responsive to removal of the load from the scale, means controlledby said switch means following removal of the load for delaying thereturn of said shaft to its no-load position pending the application ofanother load to the scale, and means operable in response to theapplication of another load to the scale for terminating the operationof said delaying means and for causing said shaft to be rapidlydisplaced to a position corresponding to the other said load.

11. In a power operated scale having a platter and support means forsaid platter incorporating parts arranged for relative movement inresponse to application of a load to said platter and including a leveradapted to occupy a no-load balance position and to be deflected to anew balance position corresponding to the load on said platter, thecombination of a drive motor having a shaft, means responsive to thedeflections of said lever for controlling the energization of said motorin forward or reverse directions selectively to establish a balanceposition of said shaft corresponding to each balance position of saidlever, mechanism operated by said shaft in response to establishment ofa balance position thereof for automatically producing an indication ofthe weight corresponding to said balance position, switch means carriedby said relativelymovable parts of said platter support 13' means forrelative movement between a no-load position when no load is on saidplatter and a load position in response to relative movement'of saidparts caused by application of a load to said platter, means maintainingsaid switch means in said no-load position thereof over a predeterminedsmall range of movement of said lever from said no-load balance positioncorresponding to a predetermined small weight, and means actuated bysaid switch means in said no-load position thereof for blockingoperation of said indicating mechanism to prevent said automaticoperation of said indicating mechanism upon establishment of a balanceposition of said shaft corresponding to said no-load position of saidlever or to a balance position of said lever within said predeterminedsmall range.

12. In a power operated scale having a platter and support means forsaid platter incorporating parts arranged for relative movement inresponse to application of a load to said platter and including a leveradapted to occupy a no-load balance position and to be deflected to anew balance position corresponding to the load on said platter, thecombination of a drive motor having a shaft, means responsive to thedeflections of said lever for controlling the energization of said motorin forward or reverse directions selectively to establish a balanceposition of said shaft corresponding to each balance position of saidlever, mechanism operated by said shaft in response to establishment ofa balance position thereof for automatically producing an indication ofthe weight corresponding to said balance position, switch means carriedby said relatively movable parts of said platter support means forrelative movement between a no-load position when no load is on saidplatter and a load position in response to relative movement of saidparts caused by application of a load to said platter, means actuated bysaid switch means in said no-load position thereof for blockingoperation of said indicating mechanism to prevent said automaticoperation of said indicating mechanism upon establishment of a balanceposition of said shaft corresponding to said no-load position of saidlever, means biasing said switch means to said no-load position thereof,and said biasing means being of a predetermined force maintaining saidswitch means in said no-load position over a predetermined small rangeof movement of said lever from said no-load balance position to maintainsaid blocking operation of said switch means except when the load onsaid platter is in excess of a corresponding predetermined small weight.

13. A power operated scale adapted for the rapid weighing of a series ofloads and having a weighing mechanism including a platter and a leveradapted to occupy a no-load balance position and to be deflected to anew balance position corresponding to the load on said platter,comprising a reversible drive motor having a shaft adapted to bedisplaced from a no-load balance position to a balance positioncorresponding to the weight on said platter, control means actuated inresponse to deflections of said lever for selectively controlling theenergization of said motor to cause displacement of said shaft in anamount proportional to the load on said platter, mechanism operated bysaid shaft in response to establishment of a balance position thereoffor automatically producing an indication of the weight corresponding tosaid balance position, switch means adapted to occupy a no-load positionin the absence of a load on said platter and movable to a load positionin response to the presence of a load on said platter, means responsiveto movement of said switch means from said load position to said noloadposition thereof for effecting a delayed return of said shaft to itsno-load position pending the application of another load to saidplatter, and means actuated by said switch means in said no-loadposition thereof for blocking operation of said indicating mechanism toprevent said automatic operation of said indicating mechanism upon r 14establishment of said no-load balance position of said shaft.

14. A power operated scale adapted for the rapid weighing of a series ofloads and having a weighing mechanism including a platter and a leveradapted to occupy a no-load balance position and to be deflected to anew balance position corresponding to the load on said platter,comprising a reversible drive motor having a shaft adapted to bedisplaced from a no-load balance position to a balance positioncorresponding to the weight on said platter, control means actuated inresponse to deflections of said lever for selectively controlling theenergization of said motor to cause displacement of said shaft in anamount proportional to the load on said platter, mechanism operated bysaid shaft in response to establishment of a balance position thereoffor automatically producing an indication of the weight corresponding tosaid balance position, switch means adapted to occupy a no-load positionin the absence of a load on said platter and movable to a load positionin response to the presence of a load on said platter, means responsiveto movement of said switch means from said load position to said noloadposition thereof for effecting a delayed return of said shaft to itsno-load position pending the application of another load to saidplatter, means actuated by said switch means in said no-load positionthereof for blocking operation of said indicating mechanism to preventsaid automatic operation of said indicating mechanism upon establishmentof said no-load balance position of said shaft, means biasing saidswitch means to said noload position thereof, and said biasing meansbeing of a predetermined force maintaining said switch means in saidno-load position over a predetermined small range of movement of saidlever from said no-load balance position to maintain said blockingoperation of said switch means except when the load on said platter isin excess of a corresponding predetermined small weight.

15. A power operated scale adapted for the rapid weighing of a series ofloads and having a weighing mechanism including a platter and a leveradapted to occupy a no-load balance position and to be deflected to anew balance position corresponding to the load on said platter,comprising follow-up means adapted to be displaced from a no-loadbalance position to a balance position corresponding to the weight onsaid platter, control means actuated in response to deflections of saidlever for selectively effecting displacement of said follow-up means inan amount proportional to the load on said platter, switch means adaptedto occupy a first position whenever said follow-up means is Within apredetermined small range of movement from said no-load position thereofcorresponding to a predetermined small weight on said platter, saidswitch means being movable to a second position in response to thepresence of a load on said platter in excess of said predetermined smallweight, mechanism operated by said follow-up means in response toestablishment of a balance position thereof for automatically producingan indication of the weight corresponding to said balance position whensaid switch means is in said second position thereof, and means actuatedby said switch means in said first position thereof for blockingoperation of said indicating mechanism upon establishment of a balanceposition of said follow-up means within said small range of movement.

16. A power operated scale adapted for the rapid weighing of a series ofloads and having a weighing mechanism including a platter and a leveradapted to occupy a no-load balance position and to be deflected to anew balance position corresponding to the load on said platter,comprising a reversible drive motor having a shaft adapted to bedisplaced from a no-load balance position to a balance positioncorresponding to the weight on said platter, control means actuated inresponse to deflections of said lever for selectively controlling theenergization of said motor to cause displacement of said shaft in anamount proportional to the load on said platter, switch means adapted tooccupy a first position whenever said shaft is Within a predeterminedsmall range of movement from said no-load position thereof correspondingto a predetermined small weight on said platter, said switch means beingmovable to a second position in response to the presence of a load onsaid platter in excess of said predetermined small weight, mechanismoperated by said shaft in response to establishment of a balanceposition thereof for automatically producing an indication of the weightcorresponding to said balance position when said switch means is in saidsecond position thereof, and means actuated by said switch means in saidfirst position thereof for blocking operation of said indicatingmechanism upon establishment of a balance position of said shaft withinsaid small range of movement.

17. A power operated scale adapted for the rapid weighing of a series ofloads and having a weighing mechanism including a platter and a leveradapted to occupy a no-load balance position and to be deflected to anew balance position corresponding to the load on said platter,comprising follow-up means movable in conjunction with said lever from ano-load balance position to a balance position corresponding to theweight on said platter, printing means operated in response toestablishment of a balance position of said follow-up means forautomatically producing a printed record of the weight corresponding tosaid balance position, switch means adapted to occupy a no-load positionin the absence of a load on said platter and movable to a load positionin response to movement of said weighing mechanism 16 caused by thepresence of a load on said platter, means actuated by said switch meansin said no-load position thereof for blocking operation of said printingmeans to prevent said automatic operation of said printing means uponestablishment of said no-load balance position of said follow-up means,means biasing said switch means to said no-load position thereof, andsaid biasing means being of a predetermined force maintaining saidswitch means in said no-load position over a predetermined small rangeof movement of said lever from said no-load balance position to maintainsaid blocking operation of said switch means except when the load onsaid platter is in excess of a corresponding predetermined small weight.

References Cited in the file of this patent UNITED STATES PATENTS806,752 Pevear Dec. 5, 1905 1,274,209 Tatum July 30, 1918 1,344,339Foote June 22, 1920 1,352,880 Davis Sept. 14, 1920 1,629,221 MacNutt May17, 1927 1,690,679 Hebden Nov. 6, 1928 1,838,084 Drake Dec. 29, 19312,040,072 Brendel May 12, 1936 2,346,117 Stabler Apr. 4, 1944 2,392,023Cooper Jan. 1, 1946 2,530,749 Yardeny Nov. 21, 1950 2,615,148 CritophOct. 21, 1952 2,678,206 Muldoon May 11, 1954 2,751,538 Beitz June 19,1956 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION August 9 1960Patent N00 2,948,523

Kenneth Cc Allen It is hereby certified that error appears inthe-printed specification of the above "numbered patent requiringcorrection and that the said Letters Patent should read as correctedbelow.

strike out "place, As the balance point "operations and insert the sameafter Column 6, line l column 12, line 16, after is approached, contactstakes" in line 75, same column 6;

""mechanism" strike out the commac.

Signed and sealed this 4th day of April 1961.,

(SEAL) Anew ERNEST w. SWIDER XAQXXXXQKXNX ARTHUR W. CROCKER ActingCommissioner of Patents Attesting Oflicer UNITED STATES PATENT OFFICECERTIFICATE OF CORRECTION August 9 1960 Patent N0 2,948,523

Kenneth Co Allen ears in the-printed specification It is herebycertified that error app rection and that the said Letters of the abovenumbered patent requiring cor Patent should read as corrected below.

strike out "'place, As the balance point after "operations and insertthe same line 16 after Column 6 line l is approached, contacts takes" inline '75 same column 6; col

["mechanism" strike out the comma,

Signed and sealed this 4th day of April 1961,

(SEAL) ERNEST w. SWIDER XAQXXXXQKXWX ARTHUR w. CROCKER ActingCommissioner of Patents Attesting Officer

